# List of critical infrastructure operators in the Yvelines department
Tamtam tracks 41 critical infrastructure operators headquartered in the Yvelines department. This list ranks the 30 largest by number of employees on LinkedIn, led by Eiffage, Bouygues Energies & Services and Banque Populaire Val de France. Their median headcount is 338. Half of them were founded in 1996 or later. The most common headquarters are Velizy-Villacoublay (4), Versailles (4) and Guyancourt (3).
This selection of large critical infrastructure operators in Yvelines highlights significant employers in construction, environmental services, and public administration. Companies like Eiffage, with 7684 employees, and Bouygues Energies & Services, with 5960 employees, are prominent in building and maintaining essential infrastructure. Other key players include Banque Populaire Val de France in banking, SDIS 78 for fire and rescue, and ENSIO in telecommunications.
The data shows a strong presence of public and semi-public entities, alongside large private groups. A notable cluster of headquarters is found in Versailles, home to SDIS 78, Service d鈥檌nfrastructure de la D茅fense, and CPAM des Yvelines, indicating a concentration of administrative and public service functions in the historic city.
馃嚝馃嚪 Yvelines 路 30 companies 路 Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Eiffage](https://www.tamtam.ai/c/eiffage) (eiffage.com)
Join a close-knit company valuing teamwork, innovation, and individuality to build a human-sized future, welcoming diverse talents to thrive | Construction | 馃嚝馃嚪 Velizy-Villacoublay | 7,684 | |
| 2 | [Bouygues Energies & Services](https://www.tamtam.ai/c/bouygues-energies-and-services) (bouygues-es.fr)
Bouygues Energies & Services is a key player in energy and digital transition, focusing on sustainable solutions and workforce development | Environmental Services | 馃嚝馃嚪 Guyancourt | 5,960 | |
| 3 | [Banque Populaire Val de France](https://www.tamtam.ai/c/banque-populaire-val-de-france) (banquepopulaire.fr)
This cooperative provides banking and insurance services, helping 550,000 clients and 132,700 members realize their personal and professional life projects. | Banking | 馃嚝馃嚪 Montigny-le-Bretonneux | 1,524 | |
| 4 | [SDIS 78](https://www.tamtam.ai/c/sdis-78) (sdis78.fr)
Public establishment managing fire and rescue services in Yvelines, under mayors and prefects. Responsible for operations, personnel, and equipment. | Government Administration | 馃嚝馃嚪 Versailles | 1,061 | 1996 |
| 5 | [ENSIO](https://www.tamtam.ai/c/ensio) (ensio.eu)
Specialized teams provide turnkey solutions for digital networks, energy networks, and maintenance services with a focus on sustainability and safety. | Telecommunications | 馃嚝馃嚪 Velizy-Villacoublay | 964 | 2008 |
| 6 | [Eiffage Rail](https://www.tamtam.ai/c/eiffage-rail) (eiffagerail.com)
Specializes in rail infrastructure construction, maintenance, and modernization, providing comprehensive solutions for railway networks and urban transit systems. | Rail Transportation | 馃嚝馃嚪 Velizy-Villacoublay | 938 | |
| 7 | [SEPUR](https://www.tamtam.ai/c/sepur) (sepur.com)
With over 50 years of expertise, the company specializes in waste management and cleaning services for communities, including waste collection, recycling, and green waste processing | Environmental Services | 馃嚝馃嚪 Thiverval-Grignon | 937 | 1965 |
| 8 | [Service d鈥檌nfrastructure de la D茅fense](https://www.tamtam.ai/c/service-d-infrastructure-de-la-defense) (defense.gouv.fr)
Manages, builds, and maintains the French Ministry of Armed Forces' real estate, ensuring infrastructure support and energy control for military operations domestically and abroad. | Construction | 馃嚝馃嚪 Versailles | 850 | 2005 |
| 9 | [Credit Agricole Payment Services](https://www.tamtam.ai/c/credit-agricole-payment-services) (ca-payment-services.com)
Designing payment solutions for group entities, processing transactions, and developing innovative, secure service offerings with leading market standards. | Financial Services | 馃嚝馃嚪 Guyancourt | 736 | 1972 |
| 10 | [H么pital de Poissy-Saint-Germain-en-Laye](https://www.tamtam.ai/c/hopital-de-poissy-saint-germain-en-laye) (ghtyvelinesnord.fr)
Public hospital in Yvelines, France, providing healthcare, education, and research across eight specialized care poles for all ages | Hospitals and Health Care | 馃嚝馃嚪 Poissy | 636 | |
| 11 | [CPAM des Yvelines](https://www.tamtam.ai/c/cpam-des-yvelines) (ameli.fr)
A private organization serving the CNAM for public service, protecting over 15 million individuals by implementing healthcare policies locally in Yvelines | Government Administration | 馃嚝馃嚪 Versailles | 480 | 1981 |
| 12 | [Stellantis Financial Services UK, Germany and Austria](https://www.tamtam.ai/c/stellantis-financial-services-uk-germany-and-austria) (stellantisfinancialservices.com)
Provides vehicle finance solutions for brands within the Stellantis Group. Additionally, offers instant access and fixed-term deposit accounts in Germany. | Financial Services | 馃嚝馃嚪 Poissy | 411 | 1920 |
| 13 | [Centre Hospitalier de Plaisir](https://www.tamtam.ai/c/centre-hospitalier-de-plaisir) (ch-plaisir.fr)
Provides diverse, specialized hospital and outpatient care in South Yvelines, including radiology, MRI, and CT scans, focusing on gerontological, medico-social, and mental health. | Hospitals and Health Care | 馃嚝馃嚪 Plaisir | 349 | |
| 14 | [Centre hospitalier de Rambouillet](https://www.tamtam.ai/c/centre-hospitalier-de-rambouillet) (ch-rambouillet.fr)
Provides diverse medical services including imaging, surgery, cardiology, dialysis, emergency care, and laboratory support for local population. | Hospitals and Health Care | 馃嚝馃嚪 Rambouillet | 345 | 1731 |
| 15 | [Eiffage Concessions](https://www.tamtam.ai/c/eiffage-concessions) (eiffageconcessions.com)
The company specializes in developing sustainable infrastructure projects, focusing on transport, renewable energy, urban facilities, and quality of life improvement for communities | Facilities Services | 馃嚝馃嚪 Velizy-Villacoublay | 338 | |
| 16 | [H么pital de Mantes-la-Jolie](https://www.tamtam.ai/c/hopital-de-mantes-la-jolie) (ghtyvelinesnord.fr)
Provides comprehensive, specialized hospital care, day hospital and outpatient surgery, accommodation beds, and various specialized consultations, as part of a public hospital group. | Hospitals and Health Care | 馃嚝馃嚪 Mantes-la-Jolie | 253 | |
| 17 | [HOPITAL PRIVE DE L'OUEST PARISIEN](https://www.tamtam.ai/c/hopital-prive-de-l-ouest-parisien) (hopital-prive-de-l-ouest-parisien-trappes.ramsaysante.fr)
Multidisciplinary hospital providing high-quality medical-surgical care, established as the largest private Medicine Surgery Obstetrics (MCO) facility in Yvelines. | Hospitals and Health Care | 馃嚝馃嚪 Trappes | 202 | 1981 |
| 18 | [SAVAC](https://www.tamtam.ai/c/savac) (savac.fr)
Family-owned group, passenger road transport by coaches and buses, prioritizing reactivity and service quality for customer mobility needs. | Truck Transportation | 馃嚝馃嚪 Chevreuse | 198 | 1937 |
| 19 | [HOPITAL LE VESINET](https://www.tamtam.ai/c/hopital-le-vesinet) (hopital-levesinet.fr)
Specializing in follow-up care and rehabilitation services to support patients in their recovery and improve their overall well-being | Medical Practices | 馃嚝馃嚪 Le V茅sinet | 187 | |
| 20 | [H么pital de Meulan - Les Mureaux](https://www.tamtam.ai/c/hopital-de-meulan-les-mureaux) (ghtyvelinesnord.fr)
Provides hospital care, day care, and consultations in various specialties, part of the Yvelines Nord hospital group. | Hospitals and Health Care | 馃嚝馃嚪 Meulan-en-Yvelines | 186 | |
| 21 | [Les Sentinelles du Rail](https://www.tamtam.ai/c/les-sentinelles-du-rail) (lessentinellesdurail.fr)
Established in 2014, a railway construction safety company with ISO 9001 and OHSAS 18001 certification, growing steadily with 190 operators, focusing on excellence, quality, and agility Offering various services for railway projects | Business Consulting and Services | 馃嚝馃嚪 Buc | 126 | 2014 |
| 22 | [Colas Rail Infra Services](https://www.tamtam.ai/c/colas-rail-infra-services) (colasrail.com)
Ensuring safety on railway construction sites through human announcements, portable radio announcement devices, insulation devices, and managing work trains on closed lines. | Railroad Equipment Manufacturing | 馃嚝馃嚪 Louveciennes | 125 | 2015 |
| 23 | [HOPITAL PRIVE DE VERSAILLES](https://www.tamtam.ai/c/hopital-prive-de-versailles) (hopital-prive-de-versailles.ramsaysante.fr)
A hospital and health care facility located in Versailles, France, providing medical services to patients in the ??le-de-France region | Hospitals and Health Care | 馃嚝馃嚪 Versailles | 93 | 2009 |
| 24 | [CA-SILCA](https://www.tamtam.ai/c/ca-silca)
IT production services for Groupe Cr茅dit Agricole, including infrastructure management, cloud solutions, big data, SOC operations, and user services | IT Services and IT Consulting | 馃嚝馃嚪 Guyancourt | 83 | 2005 |
| 25 | [CASGBS - Communaut茅 d'agglom茅ration Saint Germain Boucles de Seine](https://www.tamtam.ai/c/casgbs-communaute-d-agglomeration-saint-germain-boucles-de-seine) (saintgermainbouclesdeseine.fr)
Join a dynamic intercommunal organization near Paris, dedicated to innovation in active mobility, environment, economic development, and more for the benefit of its diverse population | Government Administration | 馃嚝馃嚪 Le Pecq | 78 | 2016 |
| 26 | [Communaut茅 d'agglom茅ration Rambouillet Territoires](https://www.tamtam.ai/c/communaute-d-agglomeration-rambouillet-territoires) (rt78.fr)
Management of community space, economic growth, infrastructure, environment, culture, sports, generational actions, sanitation, and sustainable development across 36 communes. | Government Administration | 馃嚝馃嚪 Rambouillet | 76 | 2004 |
| 27 | [Sitreva](https://www.tamtam.ai/c/sitreva) (sitreva.fr)
A syndicate managing waste treatment and disposal for its members in France, operating waste collection services and recycling centers | Government Administration | 馃嚝馃嚪 Rambouillet | 51 | 1994 |
| 28 | [Clinique Saint-Germain - Vivalto Sant茅](https://www.tamtam.ai/c/clinique-saint-germain-vivalto-sante) (cliniquesaintgermain.vivalto-sante.com)
Operates as a multidisciplinary health facility in Saint-Germain-en-Laye, part of the third-largest national private hospitalization group. | Hospitals and Health Care | 馃嚝馃嚪 Saint-Germain-en-Laye | 49 | 2009 |
| 29 | [Centre Cardiologique d鈥橢vecquemont - Vivalto Sant茅](https://www.tamtam.ai/c/centre-cardiologique-d-evecquemont-vivalto-sante) (cardiologie-evecquemont.fr)
A healthcare center specializing in cardiovascular care, geriatrics, sleep disorder diagnostics Affiliated with Vivalto Sant茅 group, serving 5,500 patients annually | Hospitals and Health Care | 馃嚝馃嚪 Evecquemont | 48 | 1959 |
| 30 | [Centre Hospitalier de la Mauldre](https://www.tamtam.ai/c/centre-hospitalier-de-la-mauldre) (chmauldre.fr)
Medical practice company in 脦ledefrance, France, focused on providing healthcare services at 23 Rue Saint Louis, Jouars Pontchartrain | Medical Practices | 馃嚝馃嚪 Jouars-Pontchartrain | 47 | |
## How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.
## More company lists in the Yvelines department
- [The largest companies in the Yvelines department](https://www.tamtam.ai/l/largest-companies-yvelines) (1,469)
- [Multinational companies in the Yvelines department](https://www.tamtam.ai/l/multinational-companies-yvelines) (226)
- [Companies with in-house R&D in the Yvelines department](https://www.tamtam.ai/l/r-and-d-companies-yvelines) (160)
- [IT services companies in the Yvelines department](https://www.tamtam.ai/l/it-services-companies-yvelines) (121)
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- [Manufacturers in the Yvelines department](https://www.tamtam.ai/l/manufacturers-yvelines) (109)
- [Professional services firms in the Yvelines department](https://www.tamtam.ai/l/professional-services-firms-yvelines) (108)
- [Hardware manufacturers in the Yvelines department](https://www.tamtam.ai/l/hardware-companies-yvelines) (106)
- [Distributors and wholesalers in the Yvelines department](https://www.tamtam.ai/l/distributors-and-wholesalers-yvelines) (91)
- [Retail chains in the Yvelines department](https://www.tamtam.ai/l/retail-chains-yvelines) (89)
- [Consulting firms in the Yvelines department](https://www.tamtam.ai/l/consulting-firms-yvelines) (72)
- [Aerospace and defence companies in the Yvelines department](https://www.tamtam.ai/l/aerospace-and-defense-companies-yvelines) (65)
- [Public sector organisations in the Yvelines department](https://www.tamtam.ai/l/public-sector-organisations-yvelines) (65)
- [Software Development companies in the Yvelines department](https://www.tamtam.ai/l/software-development-companies-yvelines) (56)
- [Business Consulting and Services companies in the Yvelines department](https://www.tamtam.ai/l/business-consulting-and-services-companies-yvelines) (53)
- [Government Administration companies in the Yvelines department](https://www.tamtam.ai/l/government-administration-companies-yvelines) (51)
- [Construction companies in the Yvelines department](https://www.tamtam.ai/l/construction-companies-yvelines) (50)
- [Automotive manufacturers and suppliers in the Yvelines department](https://www.tamtam.ai/l/automotive-companies-yvelines) (49)
- [Motor Vehicle Manufacturing companies in the Yvelines department](https://www.tamtam.ai/l/motor-vehicle-manufacturing-companies-yvelines) (49)
- [SaaS companies in the Yvelines department](https://www.tamtam.ai/l/saas-companies-yvelines) (49)
- [Education providers in the Yvelines department](https://www.tamtam.ai/l/education-companies-yvelines) (46)
- [Industrial Machinery Manufacturing companies in the Yvelines department](https://www.tamtam.ai/l/industrial-machinery-manufacturing-companies-yvelines) (43)
- [Family-owned companies in the Yvelines department](https://www.tamtam.ai/l/family-owned-companies-yvelines) (36)
- [Environmental services companies in the Yvelines department](https://www.tamtam.ai/l/environmental-services-companies-yvelines) (35)
## The same list elsewhere in France
- [Critical infrastructure operators in France](https://www.tamtam.ai/l/critical-infrastructure-operators-france) (2,721)
- [Critical infrastructure operators in 脦le-de-France](https://www.tamtam.ai/l/critical-infrastructure-operators-ile-de-france) (780)
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- [Critical infrastructure operators in Hauts-de-France](https://www.tamtam.ai/l/critical-infrastructure-operators-hauts-de-france) (174)
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- [Critical infrastructure operators in Brittany](https://www.tamtam.ai/l/critical-infrastructure-operators-brittany) (120)
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- [Critical infrastructure operators in Centre-Val de Loire](https://www.tamtam.ai/l/critical-infrastructure-operators-centre-val-de-loire) (87)
- [Critical infrastructure operators in the Nord department](https://www.tamtam.ai/l/critical-infrastructure-operators-nord) (87)
- [Critical infrastructure operators in Bourgogne-Franche-Comt茅](https://www.tamtam.ai/l/critical-infrastructure-operators-bourgogne-franche-comte) (76)
- [Critical infrastructure operators in the Haute-Garonne department](https://www.tamtam.ai/l/critical-infrastructure-operators-haute-garonne) (64)
- [Critical infrastructure operators in the Gironde department](https://www.tamtam.ai/l/critical-infrastructure-operators-gironde) (63)
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- [Critical infrastructure operators in the H茅rault department](https://www.tamtam.ai/l/critical-infrastructure-operators-herault) (57)
- [Critical infrastructure operators in the Seine-Saint-Denis department](https://www.tamtam.ai/l/critical-infrastructure-operators-seine-saint-denis) (53)
- [Critical infrastructure operators in the Seine-Maritime department](https://www.tamtam.ai/l/critical-infrastructure-operators-seine-maritime) (46)
- [Critical infrastructure operators in Paris](https://www.tamtam.ai/l/critical-infrastructure-operators-paris) (331)
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Source: https://www.tamtam.ai/l/critical-infrastructure-operators-yvelines